The invention concerns urea being heated with other organic compounds containing an active hydrogen and other active radicals to produce urea-organic compounds condensate. The invention also concerns their preparation and use. The urea-organic compound condensates are useful to produce flame retardant plastics, natural products, resins and compounds. These flame retardant resins and compounds may be reacted with phosphorus and/or boron containing compounds to produce other flame retardant compounds. The urea-organic compound condensate resins and compounds may also be reacted with aldehydes to produce urea-organic compounds condensate-aldehyde resins for use as molding resin or as a flame retardant compound. The urea-organic compound condensates will react with polyisocyanates to produce foams for insulation and other products. The urea-unsaturated polyester condensate will react with unsaturated compounds such as styrene in the presence of a catalyst to produce flame retarded polyester resins.
The heating of urea with other organic compounds to produce flame retardant, urea-organic compounds condensates, is novel. The condensation of isocyanuric acid and/or cyanic acid, (which are produced by heating urea),with other reactive organic compounds to produce flame retardant resins and compounds is novel. The urea-organic compound condensates and their phosphorus and/or boron salts are used as flame retardant compounds in plastics and natural products. Urea and melamine were utilized as a flame retardant compound by Fracalossi, et al., in U.S. Pat. No. 4,385,131. Melamine was utilized as flame retardant compounds in polyurethanes by Yukuta, et al., in U.S. Pat. No. 4,221,875 and by Grinbergs et al., in U.S. Pat. No. 4,745,133. Amino phosphates was utilized by Blount in U.S. Pat. No. 5,010,113.
What is lacking and what is needed are useful inexpensive nitrogen containing organic resins and compounds with a plurality of nitrogen moieties. The urea-organic compound condensate and/or their salts of this invention are novel flame retardant compounds. What is additionally lacking are compositions having such urea-organic compound condensates and/or their salts employed therein.
In one aspect, the invention comprises urea-organic compounds condensates. Another aspect of the invention is a process to prepare urea-organic compound condensate comprising serially contacting
(A) urea
(B) organic compounds with active hydrogen or radical that will condensate or react with urea;
under conditions sufficient to prepare the urea-organic compound condensate;
(C) water;
the urea and the reactive compound are mixed, heated and reacted. The water may be added to the condensate then heated or may be added with the urea and organic compound before heating or utilized to make emulsions.
In another aspect, the invention comprises urea condensation-organic compound condensate salt of phosphorus and/or boron containing compound and a process to prepare a urea-organic compound condensate salt of a phosphorus and/or boron containing compound employing phosphorus and/or boron containing compound that will react with the urea-organic compound condensate under conditions sufficient to prepare the urea-organic compound condensate salt of a phosphorus and/or boron containing compound, and a process to prepare a urea-organic compound condensate salts of a phosphorus and/or a boron containing compound comprising serially contacting
(A) urea
(B) organic compound that will condensate or react with urea
(D) phosphorus and/or boron containing compound that will react with a urea-organic compound condensate.
An addition aspect of this invention is the production of urea-organic compound condensate-aldehyde resins and a process to prepare urea-organic compound condensate-aldehyde resins under conditions sufficient to prepare the urea-organic compound condensate-aldehyde resin comprising serially contacting
(A) urea
(B) organic compound that will condensate or react with urea
(C) water
(E) aldehyde
(J) a basic or acidic catalyst
An additional aspect of the invention is use of the urea-organic compound condensates in the production of urea-organic compound condensate salts of phosphorus and/or boron compounds and in the production of urea-organic compound condensate-aldehyde resins. The flame retardant use comprises contacting an otherwise more flammable organic material with the urea-organic compound condensate and/or urea-organic compound condensate salts of phosphorus and/or boron containing compounds and/or urea-organic compound condensate-aldehyde resins and/or urea-organic compound condensate composition thereof under conditions sufficient to lower the combustibility of the flammable organic material, for example plastics, natural products or polyurethanes. Thus, a further aspect of the invention is a flame-retardant composition comprising an otherwise more flammable organic material incorporated therewith a flame retardant amount of a urea-organic compound condensate and/or a urea-organic compound condensate salt of a phosphorus and/or boron containing compound, and/or urea-organic compound condensate-aldehyde resin, carbonization auxiliaries and fillers.
The flame-retardant resins and compounds of this invention are produced by heating urea (Component A) with a reactive organic compound (Component B) to above the melting point of urea to about 140-170 degree C. at ambient or elevated pressure for 1-3 hrs. Upon heating above the melting point urea form a very reactive compound isocyanic acid and/or cyanic acid which will react with itself or other organic or inorganic compounds especially organic compounds which have reactive hydrogens. In order to increase the flame retardant properties and carbonization properties of the urea-organic compound condensate, a carbonization auxiliary, such as, phosphorus acidic compounds, organic phosphorus compounds, boron compounds, etc., that will react with a urea-organic compound condensate, is added to the melted urea-organic compound condensate, mixed and/or reacted. Other carbonization auxiliaries may be mixed with the urea-organic compound condensate to produce the flame retardant urea-organic compound condensate composition. The urea condensation-organic compound condensate may be further reacted with an aldehyde in the presence of a neutral or basic or acidic catalyst by mixing and heating the urea-organic compound condensate with the aldehyde, usually in an aqueous medium, to just below the boiling point of the components at ambient or an elevated pressure thereby producing a urea-organic compound condensate-aldehyde resin. Fillers and carbonization auxiliaries may be added to or reacted with the urea-organic compound condensates or the urea-organic compound condensate-aldehyde resin. The urea-organic compound condensates and urea-organic compound condensate-aldehyde resins with or without carbonization auxiliaries and fillers may be reacted with or added to or applied to a more flammable organic material.
Urea is utilized as component A and may be in the form of a powder, crystals or a solid. Any suitable urea may be utilized that will react with a reactive organic compound. Urea is utilized in the amount of 50 to 100 parts by weight.
Any suitable reactive organic compound, except amino compounds which must be added with another organic compound, that will react with isocyanic acid and/or cyanic acid may be utilized in this invention. Suitable organic saturated, unsaturated or substituted compounds may be an aliphatic, aromatic, cyclic, aliphatic-aromatic or aliphatic-cyclic compound such as, but not limited to, alcohols, polyalcohols, epoxides, polyepoxides, epihalohydrins, organic acids, polycarboxylic acids and hydrides, thioalcohols, phenols, thiophenols, halogenated alcohols and polyalcohols, halogenated organic compounds, halogenated organic acids and polycarboxylic acids, sulphonic acid chlorides, organic ester, organic ethers, thioethers, ketones, nitriles, sulphonic acids, imides, alkyl carbonates, oils, fats, carbohydrates, cellulose, lignin, wood flour, acrylic acid, alkyl acrylic acids, allyl alcohol, allyl chloride, polyvinyl alcohol, organic phosphates, phosphites, phosphonates and phosphorus esters, alkyl chlorophosphines, phosgene, ammonium carbonate, alkyl carbamates, alkyl isocyanates, polyisocyanates, sulfamic acid, ammonium sulfamate, amino compounds, amines, polyamines,, thioureas, alkylanolamine, polyamides with free xe2x80x94NH or xe2x80x94COOH radicals, amidines, amides, aldimines, ketimines, polyester with free xe2x80x94OH or COOH radicals and mixtures thereof,
The organic compound may contain one or more of the following radicals:
xe2x80x94Cl, xe2x80x94Br, xe2x80x94F, xe2x80x94OH, xe2x80x94COOH, xe2x80x94CN, xe2x80x94NO, xe2x80x94COCl, xe2x80x94COBr, xe2x80x94NCO, xe2x80x94Cxe2x95x90Cxe2x80x94, xe2x80x94NH,

xe2x80x94SO OH, xe2x80x94SH, xe2x80x94SiCl
and mixtures thereof.
Suitable epoxy compounds include but not limited to alkyl epoxide such as ethylene oxide, propylene oxide, butylene oxides, trichlorobutylene oxide, epihalohydrins, 2,3-epoxybutane, 1,2-epoxydecane, 1,2,-epoxyactadecane; unsaturated ether, epoxide such as ally glycedyl ether; dialkylatable epoxides such as tert-butyl glycidyl ether; and other polyepoxides and mixtures thereof. The epihalohydrins are preferred.
Any suitable alcohol or polyalcohols may be chemically reacted, suitable alcohols include, but are not limited to, aliphatic alcohols such as methanol, ethanol, sec-butanol, 1-buten-4-ol and propargyl alcohol and substituted alcohols such as 2-fluoroethanol, 2-chloroethanol, 2-bromoethanol, 2-cyanoethanol; aromatic alcohols such as phenol and benzyl alcohols and mixtures thereof. Alkyl alcohols are preferred.
Suitable polyalcohols include, but are not limited to, diols such as ethylene glycol, propylene, glycol butylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, triols such as 1,2,-propanetriol, 1,2,3-butanetriol, 1,2,10-decanetriol, 2,2-bis(hydroxymethyl)-1-octanol and 2-methyl-2-(2-hydroxyethoxy)-1-1,3-propanediol, sucrose, sucrose amine polyols, polypropylene polyols, polybutylene polyols, phenyl polyols, phenylamine polyols, polyether polyols, polyepichlorohydrin, polyepibromohydrin, sorbitol, pentaerythritol, polythioether polyols, polyacetal polyols, polycarbonate polyols, polyester polyols, polyesteramide, polyamide polyol, modified or unmodified natural polyols, carbohydrates, cellulose and mixtures thereof. The polyols may contain halo, cyano, ether, thioether, sulfoxy and ocyl ester radicals. The carbohydrate polyols are the preferred polyol.
Any suitable isocyanate may be used in this invention, organic polyisocyanates are preferred. The commercial available ones are preferred such as tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, polymethylene polyphenyl isocyanate, diphenyt methane 4,4xe2x80x2diisocyanate, 3-methyldiphenyl-methyane-4,4-diisocyanate, m-and-p-phenylenediisocyanate, polyphenylpolymethyleneisocyanates obtained by phosgenation, commercially known as xe2x80x9ccrude MDIxe2x80x9d, modified polyisocyanates and mixtures thereof. Suitable organic polyisocyanates are exemplified by the organic diisocyanates which are compounds of the general formula:
Oxe2x95x90Cxe2x95x90Nxe2x80x94Rxe2x80x94Nxe2x95x90Cxe2x95x90O
wherein R is a divalent organic radical such as an alkylene, aralkylene or arylene radical. Such radicals contain 2 to 20 carbon atoms. Unsaturated isocyanate compounds may also be used.
Urethane catalyst such as tertiary amines, alkali metal salts of weak acids, inorganic bases, organometallic compounds such as organotin compounds may be used in the invention. Surfactants and foam stabilizers such as a monhydrolyzable silicone glycol copolymer may also be used in this invention. Surfactants may also be used to assist in the dispersion of the powdered urea-organic compound condensate in aqueous solutions or emulsions and in plastics. Any suitable surfactant may be used such as ionic, cationic and non-ionic surfactants. The urethane catalyst and surfactants may be used in the amount of 0.25 to 10 percent by weight, percentage based on the weight of the Urea-organic compound condensate. Any silicone surfactant, polyurethane catalyst and polyisocyanate may be used in this invention.
Any suitable polylurethane blowing agent may be used such as halogenated alkanes, alkanes, compressed air, organic gases, etc. Compounds which decompose at temperatures above room temperature with liberation of gases may also be used as a blowing agent. The blowing agent may be used in the amount of 1 to 20 percent by weight, percentage based on the weight of the urea-organic compound condensate.
Any suitable carbonization auxiliaries may be utilized in this invention. Suitable carbonization auxiliaries are compounds that in the presence of fire assist the formation of a carbonization foam or char, such as, additives that produce acidic components in the pyrolysis mixture, such as phosphorus acids, boric acids or sulfuric acids. These acidic components are compounds such, for example, acids or salts, or their derivatives of sulfur, boron and phosphorus, such as, boron-phosphates, phosphates, and polyphosphates of ammonia, amines, polyamines, amino compounds, thioureas and alkyanolamines, but boric acid and its salts and their derivatives, organic phosphorus compounds and their salts, halogenated organic phosphorus compounds, their salts and their derivatives may also be used for this purpose.
Urea-organic compound condensates will react with a phosphorus containing compound , under conditions sufficient to prepare an urea-organic compound condensate salt of a phosphorus containing compound. Suitable inorganic phosphorus compounds include, but not limited to, phosphoric acid, pyrophosphoric acid, triphosphoric acid, metaphosphoric acid, phosphorous acid, hydrophosphorous acid, phosphinic acid, phosphinous acid, phosphine oxide, phosphorus trihalides, phosphorus oxyhalides, phosphorus oxide, mono-metal hydrogen phosphates, ammonia dihydrogen phosphate, bromated phosphates, alkali metal dihydrogen phosphate and halogenated phosphate-phosphite and their halides and acids, organic phosphorus compounds include, but not limited to, alkyl, cyclic, aryl and alkyl-aryl phosphorus compounds, such as, alkylchlorophosphines, alkyl phosphines, alkyl phosphites, dialkyl hydrogen phosphites, dialkyl alkyl phosphonates, trialkyl phosphites, organic acid phosphates, organic diphosphonate esters, aryl phosphites, aryl hydrogen phosphates, halogenated phosphonates esters and mixtures thereof. Urea-organic compound condensate salts of borates may be produced by contacting boric acid and urea-organic compound condensate under conditions sufficient to prepare the urea-organic compound condensate salts of borates which may also be utilized as a flame-retardant compound. Urea-organic compound condensate salt of boron-phosphates may be produced by contacting boron-phosphates and urea-organic compound condensates under conditions sufficient to prepare urea-organic compound condensate salt of boron-phosphate compounds which may also be utilized as a flame-retardant compound. The salt forming phosphorus containing compounds will react with the urea-organic compound condensate to form an urea-organic compound condensate salt of a phosphorus containing compound. Suitable inorganic nitrogen containing compounds and/or organic nitrogen containing compounds such as, but not limited to, ammonium phosphate, diammonium phosphate, ammonium polyphosphate, ammonia borate, ammonium hydrogen sulfate, quaternary ammonium salts, ammonium bicarbonate, ammonium carbonate, amino compounds, amines, polyamines, amides, polyamides, nitrites, polynitriles, etc. and mixtures thereof may be added with the organic compounds and reacted with the urea or maybe added after the urea and organic compound has reacted then reacted with the urea-organic compound condensates. The urea-organic compound condensate will further react with compounds by the urea-organic compound condensate being heated and losing more ammonia to form reactive radicals.
The nitrogen containing salts of phosphorus acids are the preferred carbonization compounds. The carbonization agents and other flame retardant agents may be used in the amount of 1 to 300 parts by weight.
Any suitable organic material which is more flammable than the urea-organic compound condensates, its salts and urea-organic compound condensate-aldehyde resin may be used in this invention. Any suitable plastic resin composition or mixtures thereof and any suitable natural organic material maybe used in this invention and mixtures thereof. These materials may be in the form of a solid, cellular suspension, emulsion or solution. Suitable plastic resin include, but not limited to, vinyl dienes, vinyl-diene copolymers, polyesters, polyester resins, phenoplasts, aminoplasts, polyepoxy resins, polyurethanes, furans, polyamides, polyimides, polycarbonates, homopolymers of such olefins as ethylene, propylene, and butylene; block copolymers, consisting of optional combination of these olefins; polymers of vinyl compounds such as vinyl chloride, acrylonitrile, methyl acrylates, vinyl acetates and styrene; copolymers of the foregoing olefins with vinyl monomers, copolymers and terpolymers of the foregoing olefins, with diene compounds; polyesters such as polyethylene terephthalate, polyester resins; polyamides such as nylon; polycarbonates, polyoxymethylene, silicones, polyethers, thioplasts, polytetrafluoroethylene, polysulfones, vinyldienes, poly(vinyl acetate), aliphatic allyl compounds, polyacrylonitrile, aliphatic dienes, polybutadiene, butadiene-acrylonitrile, butadiene-styrene copolymers, aromatic vinyl compounds, heterocyclic vinyl compounds, cyclic unsaturated compounds, urethane-epoxy resins, polyimides, urethane silicates, cellulose nitrate rayon, regenerated cellulose film cellulose acetate, cellulose esters, cellulose ethers, cyanoethyl cellulose, chlorinated rubber and mixtures thereof.
Suitable natural products include but not limited to wood, cellulose, lignin-cellulose, paper, cotton, wool, linen, dammars, copols, other natural resins, rosins lignin, natural rubber, natural proteins, e.g., soya bean protein, silk, glues, gelatin, etc.; modified cellulose, carbohydrates and mixtures thereof. Natural organic material and plastics may be mixed together. The urea-organic compound condensates, its salts and urea-organic compound condensate-aldehyde resin or urea-organic compound condensate composition maybe utilized in the amount of 10-200 percent, percentage based on the weight of the flammable organic material. The said flame retardant compounds may be mixed in, reacted with or applied on the flammable organic material.
Any suitable basic or acidic catalyst may be used in the reaction of urea-organic compound condensates with aldehydes. Suitable basic compounds include but not limited to, compounds containing alkali metal, alkaline earth metal and ammonia radicals and mixture thereof. Suitable acidic compounds include, but not limited to, halogen acids, acidic phosphorus containing compounds, acidic compounds containing sulfur, sulphonic acid halides, carboxylic acids, polycarboxylic acids, nitric acids and mixtures thereof. In some reactions basic or acidic catalytic are not necessary. The carbonization compounds may be utilized as the catalyst. A catalytic amount is utilized.
Any suitable aldehyde may be reacted with the amino condensation compounds. Suitable aldehydes include, but not limited to, formaldehyde, paraformaldehyde, acetoaldehyde, butyraldehyde, chloral, and other alkyl aldehydes, furfural, benzyl aldehyde and other aromatic aldehydes. The aldehydes are utilized in the amount of 20 to 100 parts by weight. Aqueous formaldehyde is the preferred aldehyde.
Any suitable filler may be used in this invention. The fillers that may be utilized in the flame retardant mixture are usually insoluble in the reaction mixtures. They may be inorganic substances, such as, alkali metal silicates, alkaline earth metal silicates, metal silicates, silica, metals, metal oxides, carbonates, sulphates, phosphates and borates, glass beads or hollow glass beads. Hydrated aluminum oxide is preferred. They may be organic substances, such as, amino compounds, such as urea, melamine, dicyandiamide, and other cyanuric derivatives or their formaldehyde resins, aminophosphates, amino salts of organic phosphates, phenol-aldehyde resin powder, powdered coke, graphite, graphite compounds, carbohydrates, cellulose, wood powder and mixtures thereof. The organic halide flame retardant compounds may also be added as fillers. The filler may be used in the amount of 1 to 300 parts by weight.
In general, the urea-organic compound condensates are produced by heating urea with other reactive organic compounds that will condensate or react with urea to produce urea-organic compound condensates. The heated urea first form isocyanic acid and/or cyanic acid which polymerizes with itself to form a mixture of cyanuric acid and cyamelide and/or biuret. The components of this invention may be added and mixed in any suitable order. Usually the urea and organic compound are mixed together and heated first then water maybe added to form an emulsion. The urea may be heated to form a urea condensate then mixed with water then reacted with the organic compound, or the urea and water is heated together to form a partially hydrolyzed urea condensate then it is reacted with the organic compound, or the urea maybe heated to form a urea condensate then further heated with water then reacted with the organic compound, or the urea-organic compound condensate may be heated with water to partially hydrolyzed urea-organic compound condensate
When urea is heated above the melting point of urea with another reactive organic compound under ambient or elevated pressures, such as alcohols, polyalcohols, epoxies, polyepoxies, isocyanates, polyisocyanates, etc. or other reactive organic compounds a different resin or compound is formed. When one or more moles of urea are reacted with one mol of a reactive organic compounds, such as a carbohydrate, new resin or compound are formed.
Any amount of the urea-organic compound condensate or the urea-organic compound condensate composition which includes the urea-organic compound condensate and/or its salts and urea-organic condensate-aldehyde resin may include carbonization auxiliaries and fillers suitable for this invention may be utilized. Preferably, flame retardant amounts of the urea-organic compound condensate and/or its salts and/or the urea-organic compound condensate-aldehyde resin or the urea-organic compound condensate composition are from 10 percent by weight to about 200 percent by weight of the otherwise more flammable organic materials such as polyester resins, polyepoxy resins, polyurethane components, acrylic and acrylate resins, polyacrylonitrile, polystyrene, water based resins, etc.
One method to measure this flame retardant capability is an oxygen index test. By selecting the various combinations of the urea-organic compound condensate composition to incorporate into a more flammable organic material the average limiting oxygen index (LOI) can be raised 10 to 30 percent or more when compared to otherwise comparable samples without the flame retardant urea condensation composition. For example three flexible polyurethane foams with the urea-organic compound condensate composition were raised more than 30 percent to a LOI of 31.7, 30.3 and 30.7.
When the urea-organic compound condensate composition were incorporated into rigid polyurethane foam and tested with a Bunsen burner""s 2xe2x80x3 flame held against the foam for one minute, the flame did not spread, a char was formed, and the flame went out when the flame was removed.
Various urea-organic compound condensates or compositions were incorporated into solid resins, for example, flexible polyepoxy resins, rigid polyepoxy resins, polyester laminating and flexible resin, polystyrene resin, polymethyl methyl acrylate resin, polyvinyl acetate resin, solid polyurethane, polyisoprene, acrylonitrile, etc, then tested with a Bunsen burner having a 2xe2x80x3 flame, and held against the sample for one minute, the flame did not spread, and went out when the flame was removed. The said above material were tested without the urea-organic compound condensate composition and all burned.
Various natural products such as wood shingles, paper, cotton cloth, and cardboard were coated with various urea-organic compound condensate compositions in an aqueous emulsion containing 20% by weight of the powdered urea-organic compound condensate composition then after the product had dried, they were tested by applying a 2xe2x80x3 flame from a Bunsen burner against the products, and the flame did not spread whereas the non-coated products caught on fire and burned.
The ratio of essential reactants and optional reactants which leads to the production of flame retardant compounds and compositions of this invention may vary, broadly speaking, with ranges listed with each component.